sum of digits in c using for loop

1#include <stdio.h>
2int main()
3{
4   int n, sum = 0, r;
5
6   printf("Enter a number\n");
7
8   for (scanf("%d", &n); n != 0; n = n/10) {
9      r = n % 10;
10      sum = sum + r;
11   }
12
13   printf("Sum of digits of a number = %d\n", sum);
14
15   return 0;
16}